The current invention pertains generally to the field of sensors used in the detection of carbon monoxide. In particular, this invention pertains to the use of an unheated, platinized tin-oxide catalyst in a sensor which detects the presence of carbon monoxide in the atmosphere or other oxidant-containing medium.
Since carbon monoxide is such a toxic gas, the ability to detect its presence in environmental spaces such as homes and automobiles is very important. Public awareness of this problem has produced a great demand for low priced carbon monoxide sensing devices. Sensors currently available on the market, however, exhibit extremely long response times and lack sensitivity to low concentrations of carbon monoxide. In addition, all of these low-priced sensors exhibit inordinately long recovery times after exposure to carbon monoxide.
Prior art methods utilize either complex and expensive instrumentation or devices utilizing conductance or spectroscopic techniques to detect carbon monoxide. Most detectors currently on the market are based on the change in resistance of sintered tin oxide in the presence of carbon monoxide. In addition to the problems mentioned above, the sintered tin oxide in these detectors must be heated, which requires a continuous source of power.
For the foregoing reasons, there is a need for a simple, low cost, low power carbon monoxide detector which operates at ambient temperatures. It is a primary object of the present invention to provide a carbon monoxide detector which exhibits these properties, as well as a faster response time than any other simple point-source sensor.